Personally, I would not leave it in the photo. I saw one just this
week in a magazine,and I thought it looked bad. I would photoshop
it out or photograph the piece before installing the pin back, if
I think the answer lies in your intent. Did you envision your brooch
existing with the pinstem as part of the design?
I see my pieces as existing in 3 phases.
1 on the body or pinned to a garment
2. in the case, on display, etc.
3. as an image
These 3 phases can certainly vary, but unless the pinstem is a
purposeful element of the design, I take great pains to hide them.
This can be difficult on "open" type brooches. With my work, it also
depends on how significant a piece it is. Lower end or production
pieces I don't usually photograph. They are made to be worn and not
to be out on display very long.
Hope that helps, Andy